Meriden, a city in New Haven County, Connecticut, United States. As of the 2010 census, the population of the city was 60,868. source

Area code 203 is a North American telephone area code that covers the southwestern part of Connecticut, and is overlaid with area code 475. The area codes stretch from Connecticut's western border, along its southern coast, to Madison, and north to Meriden. (The rest of Connecticut is served by the 860 area code, which is expected to be overlain with 959 on August 30, 2014.) The region encompassed by 203 and 475 roughly corresponds to the Connecticut side of the New York metropolitan area. Prior to August 28, 1995 (when the split with 860 took effect), area code 203 encompassed all of Connecticut. source

How can I locate and track (203) 600-9820 phone number?

There are two ways to locate a mobile phone:

Hardware method: The provider Metro PCS of the cell phone can locate the cell phone within a square kilometer — typical cell-tower range. The police with a court order and the NSA can get that data.

Software method: The operation system of the cell phone can get the exact location of your phone via GPS. You can get this data by installing a GPS tracking app, or login to the Google or iCloud account. You can locate an iPhone with Find my iPhone, Android with Device Manager or Samsung App and Windows Lumia phones using Find My Phone.

How to block calls or SMS from (203) 600-9820?

On Android go to the number in a phone book or in a call list, tap the Menu key ☰ and select "Add to block list" or "Block contact" option (depending on the manufacturer).

On your iPhone go to a dial list or Phone app, then select the number and tap "Block contact" in the bottom.

On Windows Lumia long press the number, tap "Settings" and "Block number" then.